92 lines
2.0 KiB
Go
92 lines
2.0 KiB
Go
package kvstore
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import (
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"encoding/binary"
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"log"
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"net"
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"time"
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)
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func (kv *KV) SyncRecv(conn net.Conn) {
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defer conn.Close()
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if kv.primary {
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panic("SyncRecv called on primary.")
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}
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if !kv.recvLock.TryLock() {
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return
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}
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defer kv.recvLock.Unlock()
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// It's important that we stop when this routine exits so that
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// all queued writes are committed to the database before syncing
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// has a chance to restart.
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w := newWriter(kv.db)
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w.Start(kv.MaxSeqNum())
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defer w.Stop()
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headerBuf := make([]byte, recHeaderSize)
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nameBuf := make([]byte, 32)
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afterSeqNumBuf := make([]byte, 8)
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afterSeqNum := kv.MaxSeqNum()
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expectedSeqNum := afterSeqNum + 1
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// Send fromID to the conn.
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conn.SetWriteDeadline(time.Now().Add(connTimeout))
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binary.LittleEndian.PutUint64(afterSeqNumBuf, afterSeqNum)
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if _, err := conn.Write(afterSeqNumBuf); err != nil {
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log.Printf("RecvWAL failed to send after sequence number: %v", err)
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return
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}
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conn.SetWriteDeadline(time.Time{})
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for {
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conn.SetReadDeadline(time.Now().Add(connTimeout))
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if _, err := conn.Read(headerBuf); err != nil {
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log.Printf("RecvWAL failed to read header: %v", err)
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return
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}
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rec, nameLen, dataLen := decodeRecHeader(headerBuf)
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// Heartbeat.
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if rec.SeqNum == 0 {
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continue
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}
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if rec.SeqNum != expectedSeqNum {
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log.Printf("Expected sequence number %d but got %d.",
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expectedSeqNum, rec.SeqNum)
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return
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}
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expectedSeqNum++
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if cap(nameBuf) < nameLen {
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nameBuf = make([]byte, nameLen)
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}
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nameBuf = nameBuf[:nameLen]
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if _, err := conn.Read(nameBuf); err != nil {
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log.Printf("RecvWAL failed to read collection name: %v", err)
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return
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}
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rec.Collection = string(nameBuf)
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if rec.Store {
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rec.Data = GetDataBuf(dataLen)
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if _, err := conn.Read(rec.Data); err != nil {
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log.Printf("RecvWAL failed to read data: %v", err)
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return
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}
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kv.onStore(rec.Collection, rec.ID, rec.Data)
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w.StoreAsync(rec.Collection, rec.ID, rec.Data)
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} else {
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kv.onDelete(rec.Collection, rec.ID)
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w.DeleteAsync(rec.Collection, rec.ID)
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}
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}
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}
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